The dashboard is one kind of control panel disposed underneath the windshield of an automobile. Typically, a dashboard is furnished with several data indicators for the driver to refer to when driving a car. FIG. 1 shows an outlook of the typical dashboards. According to FIG. 1, the data indicators provide information such as car speed, fuel gauge, shifting-gear position, seatbelt warning and etc, to show the driving conditions of the car. To facilitate the need of driving at night, the dashboards are further equipped with light control equipment.
Some carmakers have disposed digital readout indicators assisted with light-emitting functions on the dashboards. One popular case is a backlight illuminator. It is known to the people in this art, the backlight illuminator is used for increasing the lighting. The backlight color can be selected from a variety of different colors. For a monochroic liquid crystal as a backlight, usually there could be yellow, green, blue, white or else. The white light is used for color screens, for the white light includes most of the light colors. It is to be described that the light source for the backlight may be light bulbs, ELP, LED, CCFL and etc.
Taking the LED for example, the LED backlights are utilized at LCP panels, which is compact and cost-effective as well. The backlights increase the color performed by the LCD panels. The LED light is generated by three individual red, blue and green LED, which provides a color spectrum that sufficiently matches the color spectrum of the color filter of the LCD.
However, the light intensity control of the indicators assisted with light-emitting functions on the dashboards is pre-determined by the manufactures. The driver cannot adjust the light intensity of the dashboard based on the lighting condition inside the car, which may result in a potential danger when driving. Therefore, it is necessary to provide a control circuit that is capable for adjusting a backlight color of dashboards for automobiles.